What is the name of the process when a liquid changes into a gas?
When a liquid changes into a gas vaporization has occurred.
The process can either occur due to boiling or evaporation.
Boiling occurs when the vapor pressure of the liquid is raised (by heating) to the point where it is equal to the atmospheric pressure. At this point, liquid particles will vaporize to transition into the gas phase.
Evaporation occurs when particles on the surface of a liquid transition into the gas phase. This is due to the movement of particles and can occur at temperatures lower than the boiling point. Evaporation will occur more rapidly in liquids as they become warmer due to increased vapor pressure of the liquid.